Vibrator



Jan. 16, 1940. Q L, MALAN 2,187,088

VIBRATOR Filed June 27, 1938 3 Sheets-Sheet 1 n y @gg/.

G. L. MALAN Jan. 16, 1940.

VIBRATOR Filed June 2'7. 1938 5 Sheets-Sheet 2 Jan. 16, 1940. G. 1.. MALAN 2,187,088

VIBRATOR Filed June 27, 1938 3 Sheets-Sheet 3 Patented Jan. 16, 1940 UNITED STATES PTENT OFFICE 12 Claims.

This invention relates to vibrators and is particularly useful in concrete vibrators operated by compressed air and adapted to be submerged in fresh concrete to compact it in forms.

A broad object of the invention is to increase the reliability and durability of fluid-pressureactuated vibrators.

Another object is to simplify the construction of such vibrators.

Another object is to provide a pressure-actuated vibrator having a single unitary revolving element therein, which functions both as the motor element and the unbalanced vibrating element.

Another object is to provide a vibrator consisting of a casing and an eocentrically mounted rotor therein, in which the usual bearings are eliminated by causing the rotor to roll around in and be supported directly by the casing.

Still another object is to provide a rotary pump or engine structure having a stator and rotor with vanes projecting from the rotor and slidably sealing with the stator, in which all fluid inlet and outlet ports are eliminated from those portions of the stator surface against which the vanes seal.

Other objects and advantages of the invention, and the manner in which they are attained, will become apparent from the following detailed description with reference to the drawings, of a particular embodiment of the invention.

In the drawings:

Fig. 1 is a general view, showing a vibrator in accordance with the invention, positioned in a mass of fresh concrete in a form;

Fig. 2 is a longitudinal sectional view through the vibrator;

Fig. 3 is a cross section, taken approximately in the plane III-III of Fig. 2; l

Fig. 4 is a cross section, taken approximately in the plane IV--IV of Fig. 2;

Fig. 5 is a cross section, taken approximately in the plane V-V of Fig. 2; and

Figs. 6 to 1l, inclusive, are schematic diagrams illustrating the operationof the device and showing the elements in a plurality of positions which they assume during operation.

Referring, rst, to Fig. 1, there is depicted a vibrator I in accordance with the invention, submerged in a mass of freshly placed concrete 2 retained by forms 3. The vibrator I is actuated by compresed air which is introduced into the vibrator through a hose 4 extending to a source of compressed air, not shown. Exhaust air from the vibrator is vented through a larger hose B which surrounds the supply hose 4, as clearly shown. 'I'he exhaust hose 5 need be only long enough to extend above the surface of the concrete in which the vibrator I is partially, or completely, submerged ybut it is convenient to 5 extend this hose for a sufficient distance so that it can be employed to support the vibrator when it is in use and when it is being placed or removed.

'I'he vibrator I includes therewithin an element 10 which is moved in response to compressed air delivered through the hose 4 to impart vibration to the entire vibrator, which vibration is transmitted to the concrete and causes Vthe latter to be settled and compacted into desired position. l. Of course the vibrator is removed from the concrete as soon as the latter has been sufficiently compacted and before it has opportunity to set.

Referring' now to Fig. 2, the vibrator I comprises an outer casing l in the form of I a cylinder N having an upper end portion 8 formed therewith and having a removable lower end member 9 which is held in place by screws I0. The lateral inner surface I l of the casing is preferably cylindrical in shape and the inner end surfaces I2 and I3 are flat. Mounted within the casing l is a cylindrical rotor Il having fiat upper and lower ends sealing with the upper and lower end surfaces I2 and I3 of the casing. 'I'he rotor I4 is of substantially smaller diameter than the inter- I) nal diameter of the casing II, and in operation is always eccentrically positioned within the casing, contacting the latter along a line of contact and rolling around within the casing under the force of air pressure supplied thereto.

As shown to best advantage in Fig. 5, the rotor I 4 is provided with a. plurality of symmetrically spaced radially extending vanes I5a, I5b, |50 and I5d, respectively, which are mounted in slots I 8 in the rotor and always contact the inner surface 40 II of the casing to divide the space between the rotor surface and the casing surface into four separate chambers. The vanes are always maintained in contact with the casing by air pressure applied to the rear edges of the vanes within the V46 rotor in a manner to be more particularly described hereinafter.

Rotation of the rotor is effected by supplying air under pressure to the dierent chambers defined by the rotor, the rotor vanes and the casing, in suitable order, while at the same time permitting exhaust of air from other chambers. The air is supplied to and exhausted from the chambers through passages in the rotor itself, each of which passages extends from the circumu ferential surface of the rotor to one of the end surfaces of the rotor, where it cooperates with stationary supply and exhaust ports in the corresponding end of the casing.

Referring to Fig. 2, it will be observed that .the compressed air hose 4 is connected to a nipple I8 which is connected into the upper end wall 8 of the casing and defines a centrally positioned port I9 therein. 'I'his port I9 constitutes an inlet port in the end wall 8 of the casing. A similar centrally disposed inlet port I8 is provided in the lower end member 8 and is connected with the port I8 by a passage 20 in the end member 9 which communicates through a passage 2| in the casing 1 with the port I8. Hence air under pressure is applied to juxtaposed circular portions of the opposite ends of the rotor I4, and, as will appear later, passes through ports in the rotor to the peripheral surface of the rotor.

'I'he upper end portion 8 of the casing is also provided with a connecting member 22 which surrounds the nipple 8 and is connected to the exhaust hose and defines an annular passage surrounding the nipple I8. Passages 23 extend through the end portion 8 of the casing and communicate with an annular exhaust port 24 in the inner surface I2 which exhaust port ls concentrically disposed about the inlet port I8. A similar annular exhaust port 24 is provided in the lower end member 9 and is connected by passages 25 and 26 in the end member 9 and in the casing 1, respectively to one of the passages 23. The exhaust ports 24 and 24 in the opposite ends of the casing cooperate with exhaust ports extending from the end surfaces of the rotor I4 to the peripheral surface of the rotor.

In the particular embodiment of the invention disclosed, there are four of the vanes I5 and for convenience they are separately identiiled in the drawings by the letters a, b, c and d, as previously mentioned. The vanes I5 constitute radially extending barriers between the rotor and the stator and denne four distinct chambers 3M, 3lib, 30e and 30d, respectively, each of the chambers being connected by passages to one of four ports 3| in the lower end of the rotor, concentrically disposed about the axis of the rotor. The port 3| connected to each chamber is angularly disposed about the axis of the rotor in such relation to its connected chamber 30 as to cause it to register with the inlet port I9' only in predetermined position of the rotor within the casing. Thus the port 3|a is connected by a passage 32a to that portion of the surface of the rotor lying between vanes |5a and I5b and in part defining chamber 30a. In order to so position the passage 32a as not to intersect other passages, it is formed by drilling two intersecting bore holes, as shown in Fig. 5, and blocking the outer end of one of the bore holes. Of course any other known manner of forming the passages may be employed. Passages 32h, 32e and 32d, similar to passage 32a connect the remaining ports 3|b, 3|c and 32d to the chambers 30h, 30e and 30d, respectively. The passages 32b, 32e and 32d are formed in the same manner, and are differently positioned longitudinally in the rotor so as not to intersect with each other. 'I'he ports 3| are all positioned in the lower end of the rotor as the latter is illustrated in Fig. 2. A duplicate set of ports is provided in the upper end of the rotor, which ports communicate with a duplicate set of passages communicating with the peripheral surface of lthe rotor. Since the passages in the upper and lower ends o! the rotor are symmetrical with respect to each other and function merely to introduce air into each chamber 30 simultaneously from both ends of the rotor, the passages and ports in the upper end of the rotor do not need to be particularly described. It is desirable to provide duplicate ports and passages at oppolite ends of the rotor and introduce and exhaust air from both ends to avoid the creation of any end thrust on the rotor and also to provide for a larger eii'ective passage area.

Each of the passages 32 is connected by a passage 33 to the rear end of one of the slots 3l in which the vanes i5 are slidably mounted to apply air under pressure to the rear edges of the vanes and hold them against the casing. Thus the passage 32a is connected by passage 33a to the slot 84a, in which vane |5a is positioned so that the same air pressure is applied to the rear edge of vane |5a as is applied to the pocket or chamber 38a bounded on one side by vane IBa. In the same manner, each of the other vanes lib, IIc and Ild has the same air pressure applied to the rear edge thereof as is applied to one of the chambers adjacent that vane. By applying the same pressure to the rear edge of each vane, as is applied to one side of that vane, sufllcient outward force is always exerted on each vane to maintain it in good sealing relation with the wall of the casing without applying excessive force to the vane when the pressure against which it must seal is small.

As shown in Fig. 5, the four inlet ports 3| being symmetrically positioned about the axis oi.' the rotor and the inlet port I9' in the casing being centrally disposed in the casing, different ones of the four ports 3| will be successively brought into registration and communication with the stationary inlet port I9' as the rotor I4 is rolled around in the casing. As will be pointed out in detail later, each of the ports 3| is so oriented about the axis of the rotor with respect to the pocket or chamber 30 with which it is in communication, as to always apply air pressure to a pocket or pockets on the right side (with reference to Fig. 5) of the line of eccentricity of the rotor and casing so as to tend to revolve the rotor in clockwise direction about the axis of the casing or cylinder 1, the rotor rolling along the cylinder wall as it revolves so that it simultaneously rotates in counter-clockwise direction about its own axis.

In addition to the inlet ports and passages in the rotor, as described, outlet passages and ports are provided. Referring to Fig. 4, eight outlet ports are provided in each end of the rotor, these ports being divided into two sets of four each, and one port in each set communicating with one oi the four chambers 30a. Thus there are provided four outlet ports 31a, 31h, 31o and 31d, respectively, all symmetrically disposed about the rotor axis and positioned a short distance radially exterior of the inlet ports 3| and the second set of outlet ports 38a, 38h. 38e and 38d, respectively, symmetrically positioned about the axis of the rotor and positioned radially outside of the ports 31. Each of the ports 31 is communicated by a passage 39 with the pocket 3U bearing the same letter suiilx a, b,c or d. Likewise, each of the ports 38 is connected by a passage 40 with the chamber 30 bearing the same letter suffix a, b, c or d. Each of the ports 31 and 38 is positioned in the same quadrant as its connected chamber 30 but each port 81 is positioned adjacent the counterclockwise end of its associated quadrant whereas each port 38 is positioned adjacent the clockwise end of the associated quadrant. The ports 31 are so positioned radially from the axis of the rotor as to move into and out of registration with the stationary annular exhaust port 24 in the casing over the inner edge thereof, whereas the outer ports 38 are so spaced from the rotor axis as to move into and out of registration with the stationary outlet port 24 across the outer edge thereof.

In order to increase the effective passage area between the ports 31 and 38 and the stationary port 24,A the ports 31 and 38 are elongated circumferentially so that as each port 38 moves into or out oi' registration with the stationary port 24, its opening edge is substantially concentric with respect to the opening edge of the port 24.

With the rotor inlet and outlet ports 3I, 31 and 38, and the casing inlet and outlet ports I3 and 24, respectively, positioned as shown in the drawings, air supplied under pressure through the nipple I8 will be continuously supplied to successive ones of the chambers 30 and simultaneously exhausted from others of the chambers 30 in such order as to roll the rotor I4 in clockwise direction around the inside surface of the casing. This operation can be readily followed with reference to Figs. 6, 7, 8, 9 and 10, which are schematic diagrams showing the direction of air ow through different ports and passages in four successive positions of operation of the rotor. To simplify these figures, no attempt has been made to show the actual positions of the different passages through the rotor, but the position of the outer end of each active air passage in the rotor is shown, and an arrow indicating the direction of air flow has been drawn between the indicated outer ends of the passages and the ports 3|, 31 and 38 with which they are connected.

In the starting position shown in Fig. 6, the position of the rotor is such that the axis of eccentricity passes through the vane I5b. In this position the rotor inlet port 3Ia is in registration with the casing inlet port I9 and air is delivered under pressure through port 3Ia to chamber 30a. At the same time air pressure exists in chamber 30d as the result of air previously admitted to that chamber but which has been cut-oi from the inlet port I8 and has been permitted to expand. In this stage, chambers 300 and 3017 are exhausting. Thus, chamber 30o is exhausting through the rotor outlet port 38e which is in registration with the casing outlet port 24 and chamber 30h is exhausting through rotor outlet port 31h which is also in registration with the casing outlet port 24. Under the conditions described, the pressures in chambers 30a and 30h are higher than the pressures in chambers 30c and 30d, and the resultant force of all the pressures mentioned acting radially upon the rotor I4 is in a direction approximately normal to the axis of eccentricity and acting to the left, thereby tending to move the rotor bodily to the left. Of course the rotor is constrained from moving in a straight line by contact with the casing and is also restrained more or less from sliding movement along the casing wall by the contact friction so that it rolls to the left along the casing-wall.A

The rolling motion of the rotor is further aided by the fact that the pressure exerted by the air in chamber 30a on the underside of vane |5a is greater than the pressure exerted by the air in chamber 30d downwardly against the upper side of said vane. Similarly, the air pressure in chamber 30d exerts a greater force against the side of vane I5d than does the air in the chamber 30e on the other side of this vane. Therefore tangential forces are applied to the vanes I5a and I5b, urging them in counter-clockwise direction and tending further to cause the rotor I4 to roll along the casing instead of sliding therealong.

In Fig. 7 the rotor has been rolled under the impetuses of the forces developed as described into position where the axis of eccentricity extends through the vane I5c. It will be observed that the rotor inlet port 3Ia has been moved out of registration with the casing inlet port I3, but that neither of the outlet ports 31d and 38a have yet been brought into registration with the casing outlet port 24. Therefore the air in chamber 30a is still expanding and exerting propulsive force on the rotor. However, the rotor inlet port 3Ib has in this position been brought into registration With the casing inlet port I9 so that air is being supplied to chamber 30h. It will be observed from Fig. 6 that the rotor outlet port 38d is on the verge of registering with the casing outlet port 24, and such registration is well advanced in the position shown in Fig. 7, permitting the exhaust of air from chamber 30d.

Again referring to Fig. 6, in the initial position air Was exhausting from chamber 38e through the rotor outlet port 38e. In Fig. '7 port 38o has been carried out of registration with the casing port 24 but the outlet port 31e has been brought into registration with the casing port 24 so that exhaust from chamber 30e is continuing. Since air under pressure exists in chambers 30h and 30a and chambers 30e and 38d are connected to exhaust, the resultant force on the rotor is still substantially normal to the axis of eccentricity extending approximately through the vane In Fig. 8 the rotor has advanced until the plane of eccentricity extends through the'vane I5d in which position pressure air is being supplied through the rotor inlet port 3lc to chamber 30e. Expanding air is confined in chamber 30h and chambers 30a and 30d are exhausting through rotor outlet 'ports 38a and 31d, respectively.

In Fig. 9 the rotor has advanced into position with the plane of eccentricity extending through the vane I5a, in which position air is being admitted to chamber 30d. The air previously admitted to chamber 30e is still expanding and the air is being exhausted from chambers 30a and 30h.

In Fig. l the rotor has advanced until the plane of eccentricity again extends through the vane Ib and the apparatus is in exactly the same condition as in Fig. 6, the starting position, except that the vane I5b now contacts the casing at a point arcuately disposed from the point of contact in Fig. 6, a distance equal to the difference between the circumferential lengths of the casing wall and the rotor wall,A respectively. However, since the inlet and outlet ports I 9 and 24, respectively, in the casing are symmetrically positioned about the axis of the casing, the positions of the ports are operatively exactly the same in Fig, 10 as in Fig. 6.

As has been previously stated, each of the rotor passages 32, connected to one of the rotor inlet ports 3l communicates with its associated chamber 30 adjacent the counter-clockwise end thereof, whereas each of the rotor outlet passages 33, connected to a rotor outlet port 31, communicates with the associated chamber 38 adjacent the clockwise end thereof. The advantage of this arrangement will be explained with reference to Fig. 11, which is a schematic diagram similar to Figs. 6 to 10, inclusive, but showing the rotor in position half-way between the positions shown in Figs. 6 and 7, respectively, in which the plane of eccentricity lies approximately midway between the varies l5b and I5c, respectively.

It will be observed from Fig. 11 that the chamber 30h is divided into two divisions by the contact of the rotor against the casing. Air in the end of chamber 30h, adjacent the vane I5c, is being compressed by the approach of the adjacent portion of the rotor to the casing, and this air can still be exhausted through the rotor at the port 31h by virtue of the fact that the outer end of passage 39h is positioned closely adjacent the vane I5c. On the other hand, the division of chamber 30h adjacent the vane i5b is, in the position of Fig, 11, expanding by virtue of the movement of the adjacent portion of the rotor away from the casing, and is therefore in condition to receive and utilize air. Therefore the outer end of passage 32h, which communicates with the rotor inlet port 3ib, is positioned closely adjacent the vane i5b at the counter-clockwise end of chamber 30h. Of course the inlet and outlet passages, communicating with the remaining chambers 30a, 30h and 30e are similarly positioned.

It will be observed from an inspection of Fig. 5 that the passages 40, extending from the rotor ports -38 communicate with the associated chambers 30 adjacent the counter-clockwise ends thereof. Thus, whereas the port 38e is arcuately disposed adjacent the vane ld, passage 0c opens into the chamber 30e at a point arcuately adjacent the vane |50. The purpose of this construction is to prevent the orifice of any passage 40 from permitting by-pass of air past the line of contact between the casing and rotor at a time when air is being admitted through an inlet passage into the chamber. With the oriiices of the exhaust passages 4i) positioned as described, they are positioned back of the line of contact between the rotor and the stator during admission of air into the associated chamber. It is to be understood, however, that the advantage described of employing relatively long passages 40 is relatively slight and the device would be operative were the pasages 40 made short and extended to the periphery of the rotor at points closer to the ports 38. In general, however, if the passages 40 are not extended to points adjacent the counter-clockwise ends of their associated chambers, as shown in the drawings, then they should communicate with their associated chambers at points closely adjacent the clockwise ends thereof, rather than adjacent the midportions of the chambers.

Of course by differently orienting the rotor inlet and exhaust ports, the admission and exhaust of air from the chambers 30 can be advanced or retarded to vary the direction of the resultant thrust on the rotor relative to the plane of eccentricity. It might be assumed from the timing illustrated in Figs. 6 to 11 that the resultant force on the rotor at any instant instead of being exactly normal to the plane of eccentricity is slightly displaced -therefrom in such direction as to cause the rotor to leave the casing at the line of contact therewith, and thereby jump from point to point in the casing instead of rolling smoothly along the wall of the casing. However, it has been found in practice that a device constructed and timed as illustrated maintains continuous contact with the casing. This may be due in large measure to the fact that the centrifugal force resulting from the revolution oi' the rotor tends to hold it outward against the casing. Obviously, however, if necessary the timing can be so altered as to admit compressed air to each chamber 30 at a slightly later time than shown in Figs. 6 to 11, whereby the resultant air force exerted on the rotor may be in a direction such as to positively urge the rotor against the,

sumed that the casing remains stationary and:

only the -rotor moves. Actually, of course, it is only essential that relative motion of the rotor with reference to the casing take place. By virtue of the inertia of the rotor the casing itself tends to revolve about the axis oi the rotor as a center:

in one direction (opposite the direction of revolution of the rotor) and to rotate more slowly about its axis in the opposite direction. In a concrete vibrator as described, the rotation of the casing about its own axis may be prevented by the resistance of the connecting hose, but the revolving motion of the casing is resisted only by the inertia of the casing and the inertia of the concrete surrounding it. The revolving motion of the casing is therefore applied to the concrete and functions to vibrate and compact it. It may be desirable in some instances to permit free rotation of the casing about its own axis, since such rotation does not interfere with its revolving motion. In this case the hoses may be connected to the casing with swivel connectors which are well-known and need not be described and disclosed in detail.

A- device of the type described can of course be employed with substantially non-compressible fluids, such as liquids, as well as with gases, under which conditions the rotor inlet ports should be so positioned as to communicate with the chambers throughout expansion of each chamber.

Otherwise, of course, severe stresses would be applied to the machine by the actuating liquid.

It will be apparent from the description so far that two rotoroutlet ports cooperating with a stationary annular port in the casing are desirable in order to provide for the exhaust oi' air from each chamber 30 through substantially the entire time interval during which that chamber is contracting. On the other hand in the structure shown a single rotor intake port cooperating with a central circular casing port suilicies because it is desirable, when employing air or some other,

compressible fluid as the actuating medium, to cut -oil the supply to each chamber prior to full expansion of that chamber so as to utilize to some extent at least the energy of expansion of the uid. However, if a substantially noncompressible actuating fluid, such as a liquid, is employed, it may be desirable to employ an annular casing inlet port instead of a circular port and provide two rotor inlet ports for each chamber 30 adapted to move into registration with the annular inlet port over the inner edge and the outer edge thereof, respectively, exactly as the outlet ports 31 and 38 move into and out of registration with the annular exhaust ports 24, over the inner edge and the outer edge thereof, respectively.

The device described may be lubricated by introducing either continuously or intermittently a small amount of lubricating material, such as oil, with lthe air supply. Such systems of lubrication are already well-known in connection with airactuated devices, and need not be described or illustrated herein in detail.

Although the invention has been described as an engine responsive to pressure uid for producing rotary motion of a rotor within a casing, the device is, like many other rotary fluid-actuated engines, adapted to be employed as a pump instead of an engine, by driving the rotor around in the casing through means other than fluid pressure. Such motion of the rotor within the casing could be obtained, for example, by forcibly oscillating the casing as a whole with or without rotation of the latter, under which condition the inertia of the rotor would urge it to roll around within the casing to successively expand and contract the chambers 30 and cause them to successively draw in fluid through the inlet ports and exhaust it through the outlet ports.

Although for the purposes of explaining the invention a particular embodiment has been described and illustrated in detail, it will be obvious that many variations can be made from the particular structure described without departing from the invention, and the latter is therefore to be limited only as set forth in the appended claims.

I claim:

l. A vibrating machine comprising a casing defining a chamber having a continuous curved peripheral wall, a rotor of smaller lateral dimensions than the chamber positioned Within the chamber, and means for revolving said rotor within said chamber about an axis eccentric with respect to the center of gravity of the rotor, whereby unbalanced vibratory forces are developed in the rotor and applied to the casing, in which the casing surfaces defining said chamber constitute the effective bearing surfaces for supporting said rotor with respect to the casing and transmitting said vibratory forces from said rotor to the casing.

2. A vibrating machine comprising a casing defining a chamber having a continuous curved peripheral wall, a rotor of smaller lateral dimensions than the chamber positioned therewithin, and means for rolling said rotor along the peripheral surface of said chamber, in which the peripheral walls of said rotor and casing define the sole bearing surfaces for transmitting lateral forces from said rotor to said casing.

3. A machine of the type described, comprising a casing defining a chamber having a continuous curved peripheral wall and a fiat end closure wall, a rotor in said chamber adapted to move therein along said peripheral wall, vanes slidable in said rotor and extending therefrom into sealing relation with said casing and defining with the rotor and casing surfaces a plurality of separate chambers surrounding the rotor, and means for selectively supplying and exhausting fluid to and from said chambers, comprising passages in said rotor ext-ending from the peripheral surface. thereof to an end surface thereof, and passages in the end of said casing adapted to register with said passages in said rotor, the vane-contacting surface of said casing being continuous and imperforate.

4. A machine of the type described, comprising a casing defining a chamber having a continuous curved peripheral wall and end closure walls, a rotor in said chamber adapted to move tangentially along the peripheral wall thereof, vanes extending between the rotor and the casing and defining with the rotor and casing surfaces a pluv rality of separate chambers surrounding the rotor, and means including cooperating ports in said rotor and casing, respectively, for supplying uid to and simultaneously discharging fluid from different ones of said chambers so disposed in any position of said rotor as to produce an unbalanced resultant pressure force 0n said rotor in such direction as to move it tangentially along the peripheral wall of the chamber.

5. In combination, a casing defining a cylindrical chamber, a cylindrical rotor of smaller diameter than said chamber positioned therewithin and adapted to revolve around said chamber in rolling contact with the peripheral wall thereof, said rotor having a plurality of extensible vanes circumferentially spaced thereon for sealing between the rotor and casing and separating the space between rotor and casing into a plurality of circumferentially disposed compartments, said rotor having fluid passages therein extending from the peripheral surface thereof and terminating in ports in an end surface thereof for supplying and exhausting pressure fluid to and from said compartments, said casing having inlet and exhaust ports in an end thereof positioned to successively register with different rotor ports during revolution of said rotor within said chamber in such order as to connect said casing inlet ports to expanding compartment and connect said casing exhaust ports to contracting compartments in all positions of revolution of said rotor within said chamber.

6. The combination described in claim 5, in which said casing inlet and exhaust ports are concentric with respect to each other and the axis of said chamber, and are radially displaced from each other, and the rotor ports communieating with the different compartments are symmetrically disposed with respect to the axis of said rotor.

7. The combination described in claim 5, in which said casing inlet and exhaust ports are concentric with respect to each other and the axis of said chamber, but are radially displaced different distances from the chamber axis and said rotor ports include an inlet port and a separate outlet port communicating with each compartment, said rotor inlet ports being symmetrically positioned with respect to the rotor axis and the rotor outlet ports being symmetrically positioned about the rotor axis but radially displaced therefrom a different distance than the rotor inlet port, the different rotor inlet ports moving into and out of registration with the casing inlet port in predetermined order and the different rotor outlet ports moving into and out of registration with the casing outlet port in predetermined order as said rotor rolls around in said casing.

8. In combination, a cylinder defining a cylindrical chamber, a cylindrical rotor of smaller diameter than said cylinder positioned therewithin and adapted to revolve around in said cylinder in rolling contact with the peripheral wall thereof, said rotor having a plurality of extensible vanes circumferentially spaced thereon for seal- -ing between the rotor and cylinder and sepafluid passages therein extending from the peripheral surface thereof to ports in an end surface thereof for supplying and exhausting fluid to and from said compartments, said cylinder having inlet and outlet ports in an end thereof positioned to successively register with different rotor ports in such order relative to the position of the rotor in the cylinder as to supply iluid to Yexpanding compartments and to exhaust iiuid from contracting compartments, in which said casing outlet port is annular and concentric with respect to the axis of the cylinder and said rotor outlet ports include two ports for each compartment spaced radially from the rotor axis different distances, such that one moves into and out of registration with said annular, cylinder port across the outer edge thereof and the other moves into and out of registration with the annular cylinder port across the inner edge thereof.

9. The combination as described in claim 8, in which one at least of said rotor outlet ports associated with each compartment communicates directly with its associated compartment at a point in the rotor surface closely adjacent the lagging end thereof; that is, the portion of the rotor surface which contacts the cylinder last during the normal operation of the device; and the rotor inlet passage associated with each compartment communicates therewith closely adjacent the leading end of the compartment.

10. In combination, a cylinder deiining a cylindrical chamber, a cylindrical rotor of smaller diameter than said cylinder and freely iioating in said cylinder, said rotor having a plurality of extensible vanes circumferentially spaced thereon for sealing between the rotor and cylinder and separating the space therebetween into a plurality of circumferentially disposed compartments which successively expand and contract in response to rolling motion of the rotor around in the cylinder, said cylinder having radially spaced circumferentially continuous inlet and outlet ports in one end thereof, each port being concentric with respect to the cylinder axis, the said rotor having circumferential discontinuous inlet and outlet ports in the end thereof cooperating with said casing cylinder ports, there being a rotor inlet port and a rotor outlet port communicating with each of said compartments; in which all the rotor inlet ports are symmetrically positioned about the rotor axis and all the rotor outlet ports are symmetrically positioned about the rotor axis, and each rotor port is so positioned with respect to its associated compartment that during rolling motion of said rotor in said cylinder, in any position of contact of the rotor with the cylinder, said cylinder inlet and outlet ports are connected to expanding and contracting compartments, respectively.

11. A vibrator comprising a cylinder defining a cylindrical chamber, a single unitary rotor element supported by and revolvable within said cylinder about an axis displaced from the center of gravity of the rotor, whereby centrifugal forces are created in said rotor by revolution of said rotor and applied to said cylinder to vibrate the same, and means for applying unbalanced iluid pressures directly to said rotor to revolve the same in said cylinder.

12. In a device of the character described, a casing having a cavity therein and a body of relatively small size positioned within said cavity and adapted to move unrestrictedly in contact with the walls of the cavity, said body and casing having mutually cooperative ports and passages associated with a. source of motive fluid and with atmosphere to control the ilow of such motive fluid to and from` the space between said body and the walls of the cavity, whereby said body is caused to move continuously within the cavity.

GEORGE L. MALAN. 

